Natural fatty acids were separated and purified by steam distillation at 250–300°C. Corrosion rates were determined for three stainless steels 316L, 317L and Ti-stabilised 321, using weight-loss measurements after 14 days in three fatty acid fractions at 260°C. These results for stainless steels were compared with corrosion rates obtained for nickel, molybdenum and manganese by similar weight-loss measurements. Scanning electron microscopy was used to confirm pitting corrosion at the metal surface. The effects of water, low molecular weight fatty acids and impurities such as sodium salts are discussed in relation to the overall corrosion processes in steel steam distillation columns.
